import pylab as pl

size = 256, 16
dpi = 72.0
figsize = size[0] / float(dpi), size[1] / float(dpi)
fig = pl.figure(figsize=figsize, dpi=dpi)
fig.patch.set_alpha(0)
pl.axes([0, 0.1, 1, .8], frameon=False)

for i in range(1,11):
    pl.plot([i, i], [0, 1], lw=1.5)

pl.xlim(0, 11)
pl.xticks(())
pl.yticks(())
pl.show()
